# Angles Teaching Resources

Explore angles worksheets, hands-on activities, games and more resources created by teachers for your lesson plans!

This collection of math resources for elementary and middle school teachers is aligned with both TEKS and the Common Core Curriculum, and it's been stocked with everything you will need to teach students how to identify the different types of angles, measure real-life examples, determine the measure of an unknown angle and more!

Lay the groundwork for your students' understanding of geometry and spatial relationships with resources that have undergone a careful review by the math teachers on the Teach Starter team to ensure they're ready for your lesson plans and your students!

New to teaching this portion of the math curriculum? Or maybe you're just looking for fresh ways to engage your students on the topic? Read on for a primer from our teacher team, including a kid-friendly definition and a look at different types of angles and angle pairs from right to acute, complementary to adjacent and so on.

## What Are Angles? A Kid-Friendly Definition

If you're introducing angles for the first time, it can be helpful to have a kid-friendly definition on hand to start the lesson. Here's one that our teacher team likes to use!

Shapes are made up of lines and corners, or what we call vertices. Angles are the measure of those corners or vertex points.

## What Are the Different Types of Angles and Their Functions?

Depending on the grade level you're teaching, we know the types of angles you will be talking about in your classroom will likely differ. That said, here's a quick reminder of the various types of angles, along with a look at their functions, to use as a refresher.

### 1. Right Angle

Right angles measure exactly 90 degrees and look like the corners of a square. They're found in shapes such as squares and rectangles, and they're typically the first angle kids learn about in elementary school.

Right angles create stability in structures and ensure that objects fit together properly. They also help determine directions, so they play into map skills and navigation.

### 2. Acute Angle

An acute angle is one that measures less than 90 degrees but more than 0 degrees. Found all around us — from the corners in triangles to the hands of the classroom clock when it shows a time earlier than 3:00 — acute angles appear in designs and constructions anywhere a sharp or narrow corner is needed.

These angles are typically used to describe relationships in triangles and other geometric shapes.

### 3. Obtuse Angle

An obtuse angle measures more than 90 degrees but less than 180 degrees. This angle type can also be spotted in the classroom clock hands, but it appears when the time is after 3:00. Obtuse angles are also found in the shapes of many irregular polygons.

Obtuse angles can describe the bending or opening of objects, and they're used in design to create open space.

### 4. Straight Angle

Students are often surprised to find out that a straight line is a type of angle! Named a "straight angle," it measures exactly 180 degrees.

Understanding straight angles is fundamental to understanding the relationships between lines and their directions.

### 5. Reflex Angle

When you have an angle that measures more than 180 degrees but less than 360 degrees, it's called a reflex angle.

Reflex angles often appear in situations where bending or curving is important.

## Types of Angle Pairs

In addition to the types of individual angles, there are also a host of angle pairs that have a special relationship with one another.

### 1. Adjacent Angles

When you have two angles that share a common vertex and a common side but do not overlap, they're known as adjacent angles.

### 2. Vertical Angles

Vertical angles are pairs of angles that are opposite when two lines intersect. They are always congruent, which means they have the same measure.

Middle school students who are ready to learn about the properties of angles formed by intersecting lines tend to start by learning about this angle type.

They'll find these angle pairs in the letter X and at some street intersections. Learning about them will form the basis for understanding angles formed by transversals.

### 3. Complementary Angles

When a pair of angles add up to 90 degrees, they're called complementary angles. These types of angles can be adjacent or non-adjacent.

These angles can also be found right in the classroom on your clock. They're the angles created between the minute and hour hands of a clock when they add up to 90 degrees.

### 4. Supplementary Angles

Supplementary angles combine to form a straight line. This angle pair represents two angles that add up to 180 degrees when put together.

Two sets of right angles can be supplementary as their sum is 180 degrees (90 + 90 =180), and a set of obtuse and acute angles can also be supplementary.

### 5. Corresponding Angles

Corresponding angles are in the same relative position on the two parallel lines and the transversal. They have equal measures.

Corresponding angles are found when a transversal intersects two parallel lines, such as in a fence or many different architectural structures.

### 6. Alternate Interior Angles

Angles that are on opposite sides of the transversal and inside the parallel lines are called alternate interior angles. They have equal measures.

### 7. Alternate Exterior Angles

Angles found on opposite sides of the transversal and outside the parallel lines are known as alternate exterior angles. Like alternate interior angles, these also have equal measures.

Like corresponding angles, alternate interior angles and alternate exterior angles can both be found when a transversal intersects two parallel lines.

### 8. Linear Pair

A linear pair is a set of two adjacent angles that is formed when two lines intersect each other at a single point.

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### Mini-Mystery – Which Key Opens the Door?

Use knowledge of 2-D shapes and right angles to solve the mystery in this fun, logic-based activity.

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### Missing Angles – 4th Grade Math Worksheet

Download this missing angles worksheet to get your students calculating missing angles on right and straight angles.

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### Angle Sum of a Quadrilateral Worksheet

Calculate the missing angle in a variety of quadrilaterals with this one-page worksheet.

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### Printable Protractor Templates

Teach your students how to measure angles using a protractor with these 180° and 360° printable protractor templates.

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### Classifying Angles – 4th Grade Sorting Activity

Help students recognize different types of angles in everyday life with this hands-on sorting activity.

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### Drawing Angles Using a Protractor - Worksheets

A set of 3 worksheets to practice drawing angles using a protractor.

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### Christmas Angles Worksheet for 4th Grade

Identify acute, obtuse, and right angles with a Christmas Angle Worksheet for 4th Grade.

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### Color by Number Christmas - Geometry Worksheet

Use a Color by Number Christmas Geometry worksheet to practice classifying 2D and 3D shapes.

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### Christmas Math Tasks - Attributes of Shapes Activity

Combine Christmas and math with these 2D and 3D Shape Christmas Math Review Task Cards.

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### Color by Missing Angles – 4th Grade Math Worksheets

Get students to find the size of missing angles on right angles, straight angles and angles at a point with this 4th grade math worksheet with a difference!

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### Calculating Missing Angles Interactive Activity

Get your students to find missing angles with this interactive game perfect for 4th grade math lessons.

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### Angles 4th Grade Math Project – Design a Room

Turn your students into interior designers with this inquiry-based math project based on drawing and measuring angles.

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### Angle Word Problems – 4th Grade Math Worksheet

Download these angles word problem worksheets so your students can practice calculating missing angles.

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### Angle Word Problems Teaching Slides

Help your students tackle angle word problems with ease using this step-by-step problem-solving guide.

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### Building With Angles – 4th Grade Interactive Math Game

Transport your students to a local construction site to solve building-related angle problems with this interactive math game.

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### Measuring Angles in Images – 4th Grade Math Worksheets

Get your students using their protractors to measure acute, obtuse, right, straight and reflex angles with this set of differentiated angles worksheets.

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### Comparing and Naming Angles – 4th Grade Math Worksheets

Assess your students’ understanding of angle types with the set of differentiated student worksheets.

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### Monster Right Angle Finder Template

Help your students identify right angles in the environment with this monster-inspired right angle finder.

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### Types of Angles Task Cards

Explore the main types of angles with this set of 24 task cards.

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### Interior Angles of Shapes Interactive Game

Explore the interior angles of regular polygons with this detective-themed interactive maths activity.

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### Interior Angles of Shapes – Differentiated Mazes

Explore the interior angles of regular shapes with this differentiated, maze-inspired worksheet.

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### Interior Angles of Shapes Teaching Slides

Explore the interior angles of common two-dimensional shapes with this comprehensive set of teaching slides.

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### Interior Angles of Shapes Sorting Activity

Play this sorting game when learning about the interior angles of common two-dimensional shapes.

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### Types of Triangles Interactive Math Game

Explore the properties of acute, right and obtuse triangles with this interactive space adventure!

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### Classifying Triangles (By Angles) – 4th Grade Math Activity

Play this sorting game when learning how to classify triangles according to their internal angles.

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### Classifying Triangles (By Angles) – 4th Grade Math Worksheets

Practice classifying and sorting triangles based on their internal angles with this set of 3 worksheets.

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### Types of Angles Anchor Charts

Remind your students about the most common types of angles with this set of six classroom anchor charts.

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### Measuring Angles – Mystery Picture Worksheet

Find the measure of each angle and use the color guide to reveal a mystery picture with this worksheet designed for 4th-grade students.

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### Measuring and Drawing Angles – Task Cards

Improve student understanding of angle measurement with this set of 24 task cards.

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### Understanding Angles – Vocabulary Cards

Promote math vocabulary development with this set of 15 vocabulary cards focusing on angles.

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### Missing Angle Small Group Bingo

Practice how to find the measurement of a missing angle with this small group Bingo game.

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### Missing Angle Task Cards

Practice how to find the measure of a missing angle with this set of 18 task cards.